Lessons are up to you but I’ll tell you how I did it. Initially, I did everything as they came, that didn’t last long, it became too much and I dreaded doing them, I was inconsistent for so long, trying different things, trying 10 a day, 15, 20, 25, 30, 40 at different points, it all fell through, but at some point I just stuck to 20 because that’s what the community recommends for the most part, and I do it every night now even if I have to force myself. That being said, 20 isn’t enough to go the full speed, I’m able to do that because I use a reorder script to do my radicals and kanji at the necessary times to make sure I can level up with no down time.
For remembering, at one point I stopped reading the full mnemonics, I just check what radicals the kanji are made up of and make some connection in my brain to come up with the meaning, sometimes I do use them as a little basis, but sometimes the mnemonic has some unnecessary stuff so I cut out a lot. I’m pretty sure you can make connections with your brain even with aphantasia, since it doesn’t require a mental image.
Easier… I guess maybe? It’s kind of the same every level to me, but maybe compared to the beginning when I was new to the language, I’m certainly used to it now. Go take a look at the kanji in the higher levels, it looks scary, right? You won’t feel that way for long though, the radicals seriously do their job, and you don’t view kanji as random lines anymore.
As for my memory, well, you should definitely expect to forget some of the kanji you burned in the past, I have definitely, but I don’t have any plans to unburn them at the moment, maybe when I’m done with WK, but where I am now, I think the most important thing is to get familiar with the kanji, not use WK as my way of memorizing every kanji for life. Sure maybe some kanji like 人 are unforgettable, but some just might not stick until you’ve encountered it in reading a few times.
Eventually you’ll have to start reading, I read my first full JP manga at level 20. And now I’m translating a manga, it’s still not easy, but the progress is there, I’m even familiar with kanji that I haven’t even learned in WK yet because of reading.